Photoinduced Charge Carrier Dynamics of Zn鈭扨orphyrin鈭扵iO2 Electrodes: The Key Role of Charge Recombination for Solar Cell Performance
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- 作者：Hiroshi Imahori ; Soonchul Kang ; Hironobu Hayashi ; Mitsutaka Haruta ; Hiroki Kurata ; Seiji Isoda ; Sophie E. Canton ; Yingyot Infahsaeng ; Arunkumar Kathiravan ; Torbjo虉rn Pascher ; Pavel Cha虂bera ; Arkady P. Yartsev ; Villy Sundstro虉m
- 刊名：Journal of Physical Chemistry A
- 出版年：2011
- 出版时间：April 28, 2011
- 年：2011
- 卷：115
- 期：16
- 页码：3679-3690
- 全文大小：1138K
- 年卷期：v.115,no.16(April 28, 2011)
- ISSN：1520-5215
文摘
Time resolved absorption spectroscopy has been used to study photoinduced electron injection and charge recombination in Zn-porphyrin sensitized nanostructured TiO2 electrodes. The electron transfer dynamics is correlated to the performance of dye sensitized solar cells based on the same electrodes. We find that the dye/semiconductor binding can be described with a heterogeneous geometry where the Zn鈭抪orphyrin molecules are attached to the TiO2 surface with a distribution of tilt angles. The binding angle determines the porphyrin鈭抯emiconductor electron transfer distance and charge transfer occurs through space, rather than through the bridge connecting the porphyrin to the surface. For short sensitization times (1 h), there is a direct correlation between solar cell efficiency and amplitude of the kinetic component due to long-lived conduction band electrons, once variations in light harvesting (surface coverage) have been taken into account. Long sensitization time (12 h) results in decreased solar cell efficiency because of decreased efficiency of electron injection.